Founder and CEO, Pershing Square Capital Management
Bill Ackman is an activist investor: he buys large stakes in a handful of companies and then publicly pressures their boards. His portfolio is unusually concentrated, typically around ten names. Where most fund managers stay quiet until quarterly disclosures, Ackman shares his views on X almost daily, making him one of the most followable investors on this list.
Ackman is as well known for his spectacular wins as for his spectacular misses, and he is notably candid about both. For investors he is mainly useful as a source of fully worked-out investment theses: when he takes a position, he usually explains publicly why.
MBA at Harvard Business School; co-founds Gotham Partners with a classmate.
Starts Pershing Square Capital Management after Gotham is wound down.
Warns years in advance about bond insurer MBIA and is proved right.
Begins a years-long and ultimately loss-making campaign against Herbalife.
Puts on a credit hedge just before the covid crash that returns a multiple of its cost.
Sells a stake in his own management company; a planned listing of a new fund is shelved.
Quotes still to be added. Only add them together with a source and a date.
Updated: 2026-07-23
← All profiles